The present Convention shall come into force on the ninetieth day following the date of deposit of the twentieth instrument of ratification or accession. Any ratification or accession effected subsequent to the latter date shall become effective on the ninetieth day following the deposit of the instrument of ratification or accession. Article XIV The present Convention shall remain in effect for a period of ten years as from the date of its coming into force. It shall thereafter remain in force for successive periods of five years for such Contracting Parties as have not denounced it at least six months before the expiration of the current period. Denunciation shall be effected by a written notification addressed to the Secretary-General of the United Nations. Article XV If, as a result of denunciations, the number of Parties to the present convention should become less than sixteen, the Convention shall cease to be in force as from the date on which the last of these denunciations shall become effective. Article XVI A request for the revision of the present Convention may be made at any time by any Contracting Party be means of a notification in writing addressed to the Secretary-General. The General Assembly shall decide upon the steps, if any, to be taken in respect of such request. Article XVII The Secretary-General of the United Nations shall notify all Members of the United Nations and the non-member States contemplated in article XI of the following: (a) signatures, ratifications and accessions received in accordance with article XI; (b) notifications received in accordance with article XII; (c) the date upon which the present Convention comes into force in accordance with article XIII; (d) denunciations received in accordance with article XIV; (e) the abrogation of the Convention in accordance with article XV; (f) notifications received in accordance with article XVI. Article XVIII The original of the present Convention shall be deposited in the archives of the United Nations.